Git merges in Moodle 2.7.13 by Eloy Lafuente (stronk7)

commit 89a50ced1fe0967e2f0a1a8e45d826aa0094f7d7
Author: Eloy Lafuente (stronk7) <stronk7@moodle.org>
Date:   Sat, 12 Mar 2016 07:37:42 +0800
Tag:    v2.7.13

Merge branch 'install_27_STABLE' of https://git.in.moodle.com/amosbot/moodle-install into MOODLE_27_STABLE